Ketosteroid monooxygenase explained

Ketosteroid monooxygenase
Ec Number:	1.14.13.54
Cas Number:	9044-53-5

Ketosteroid monooxygenase (steroid-ketone monooxygenase, progesterone, NADPH2:oxygen oxidoreductase (20-hydroxylating, ester-producing), 17alpha-hydroxyprogesterone, NADPH₂:oxygen oxidoreductase (20-hydroxylating, side-chain cleaving), androstenedione, NADPH₂:oxygen oxidoreductase (17-hydroxylating, lactonizing)) is an enzyme with systematic name ketosteroid,NADPH:oxygen oxidoreductase (20-hydroxylating, ester-producing/20-hydroxylating, side-chain cleaving/17-hydroxylating, lactonizing).^{[1] [2] [3]} This enzyme catalyses the following chemical reaction

ketosteroid + NADPH + H⁺ + O₂

\rightleftharpoons steroid ester/lactone + NADP⁺ + H₂O (general reaction)

(1) progesterone + NADPH + H⁺ + O₂

\rightleftharpoons testosterone acetate + NADP⁺ + H₂O

(2) androstenedione + NADPH + H⁺ + O₂

\rightleftharpoons testololactone + NADP⁺ + H₂O

(3) 17alpha-hydroxyprogesterone + NADPH + H⁺ + O₂

\rightleftharpoons androstenedione + acetate + NADP⁺ + H₂O

Ketosteroid monooxygenase is a single FAD-containing enzyme that catalyses three types of monooxygenase reaction.

Notes and References

1. Book: Katagiri M, Itagaki E . Muller F . A steroid ketone monooxygenase from Cylindrocarpon radicicola . Chemistry and Biochemistry of Flavoenzymes . 1991 . 102–108 . CRC Press . Florida .
2. Itagaki E . Studies on steroid monooxygenase from Cylindrocarpon radicicola ATCC 11011. Purification and characterization . Journal of Biochemistry . 99 . 3 . 815–24 . March 1986 . 3486863 .
3. Itagaki E . Studies on steroid monooxygenase from Cylindrocarpon radicicola ATCC 11011. Oxygenative lactonization of androstenedione to testololactone . Journal of Biochemistry . 99 . 3 . 825–32 . March 1986 . 3486864 .